3D printing clear parts

[longmc]

Is it possible to make clear parts using 3D printers? Specifically, we need a frameless windscreen for the F-4 Phantom. The F-4E, G, and RF-4C all flew with them, and Speed Hunter did really good decals for 2 F-4Es and an F-4G. 

With the release of the Meng kits, now's the time! 

[JeffreyK]

It is possible to print clear resin, there are a number of them on the market. However, it would be pretty useless for this application as with the current state of tech it's impposible to hide the print artefacts, even with the best printers. Anti-Aliasing is a digital algorithm that works well hiding the remnants of the 3D "pixels " ("voxels"), and tiniest print layers make the layer steps imperceivable on normal, opaque resin prints. But this is not good enough for clear resin. You can dip the finished print back in liquid clear resin, a process similar to dipping it in Future, but this is not advisable for something as small and detailed as a scale model part, it would öiterally wash out detail, make edges and corners round...

Maybe in a few years time, or maybe someone will come up with an amazing trick just tomorrow, you never know.

J

[longmc]

Jeffrey,

great answer! Thank you. So the best option for clear parts is still injection molding? 

[signals]

I've had good luck with https://www.buildparts.com

[arnobiz]

Primary question: no, it's not possible at the moment to get optically clear resin parts directly from a printer.

 

Secondary question: BAM Models will be working on the Phantom single-piece windshield for the Meng kits soon 😉

 

Arnaud

[ElectroSoldier]

10 hours ago, JeffreyK said:

It is possible to print clear resin, there are a number of them on the market. However, it would be pretty useless for this application as with the current state of tech it's impposible to hide the print artefacts, even with the best printers. Anti-Aliasing is a digital algorithm that works well hiding the remnants of the 3D "pixels " ("voxels"), and tiniest print layers make the layer steps imperceivable on normal, opaque resin prints. But this is not good enough for clear resin. You can dip the finished print back in liquid clear resin, a process similar to dipping it in Future, but this is not advisable for something as small and detailed as a scale model part, it would öiterally wash out detail, make edges and corners round...

Maybe in a few years time, or maybe someone will come up with an amazing trick just tomorrow, you never know.

J

Have you tried it with one of the new 8k printers?

 

I must say my first thought was not without voxel lines but Ive not tried any clear resins, only the Phrozen 8k grey resin

[Inquisitor]

5 hours ago, ElectroSoldier said:

Have you tried it with one of the new 8k printers?

 

I must say my first thought was not without voxel lines but Ive not tried any clear resins, only the Phrozen 8k grey resin

JeffreyK above from Hypersonic models has been using a pair of Phrozen Sonic Mini 8k with 22um resolution for his resin products, it's the highest resolution printer in the consumer market without going for industrial class 3d printers and their cost and even those need post processing. If he says optical clear parts OOB without coating is not possible, it's probably because he already tested.

 

Edited March 1, 2023 by Inquisitor

[ElectroSoldier]

4 hours ago, Inquisitor said:

JeffreyK above from Hypersonic models has been using a pair of Phrozen Sonic Mini 8k with 22um resolution for his resin products, it's the highest resolution printer in the consumer market without going for industrial class 3d printers and their cost and even those need post processing. If he says optical clear parts OOB without coating is not possible, it's probably because he already tested.

 

What do you mean by "post processing" exactly?

[Inquisitor]

6 hours ago, ElectroSoldier said:

What do you mean by "post processing" exactly?

As explained by Jeffrey, clear parts coming from a 3D printer still need to be sanded, polished and dipped in clear varnish to make them optically clear and smooth. Even if it was printed in opaque resin to use them as master for making silicone molds and casting them in conventional clear resin, that would be even more important to do beforehand. Like the old adage 'crap in crap out'. If you make a mold with masters still showing layer lines and voxels, the resin pieces coming out those molds will show the same layer lines and voxels. As examples, every conventional clear resin parts from Eduard are optically clear and polished. While I have several early res-kit sets where their conventional clear resin parts show layer lines and voxels, evidence that they didn't bother to sand and polish their masters before making the molds.

[JeffreyK]

Using printers with very small pixel LCD's ("8K printers", although you always need to know what the overall size of the screen is, otherwise it won't say much about the size of the actual pixel), small layer steps, good resins, Anti-Aliasing (eplained above) and clever part orientation (takes a lot of experimentation, as no part is qutie like another), you can minimise the print artefacts so much these days that they are either not noticeable at all or only present on sorfaces that are nor relevant, i.e. hidden.

Setting up a 3D printed master is relatively straightforward in that you prime, sand and polish (sometimes in extremely small areas) until all steps etc. are gone so you don't need to worry that much in the print process. Making 3D printed parts for direct sale is more labour intensive at the beginning as you really need to test and repeat to find that sweet spot where you get a smooth surface. But once you've nailed this, production is then less work as the printer does that job (unless something goes wrong of course...).

But clear resins are just different in that artefacts pretty much impossible to hide, no matter what. Printed parts have a naturally matte surface - "smooth" doesn't mean glossy or polished.

Also, another phenomenon comes into play and that is that 3D printers have the nasty habit of introducing tiny bubbles onto the parts. You can minimise this with a number of measures but it's really hard to get rid of them completely, I think it's an inherent part of the process. It's not a big concern with opaque parts, but of course a major issue with clear parts.

J

[ElectroSoldier]

Im thinking of the Phrozen Aqua Resin Clear printed with a Sonic Mighty 8k printer.

 

Purely thinking about home use here.
If you modelled a simple part, say a wind screen for an Italeri Opel Blitz truck 1:35 and printed it in that clear resin what would you say it would turn out like?

[Inquisitor]

49 minutes ago, ElectroSoldier said:

Im thinking of the Phrozen Aqua Resin Clear printed with a Sonic Mighty 8k printer.

 

Purely thinking about home use here.
If you modelled a simple part, say a wind screen for an Italeri Opel Blitz truck 1:35 and printed it in that clear resin what would you say it would turn out like?

The opel blitz truck windshield is flat enough that you'd get away with just cutting it out from clear plastic sheet. Even a lot of resin car kits get away with that. 3d printing is not the miracle tool for everything. That's one thing you learn. It not a question of if you can, but should you? My brother got that fever a few years back when he got his first FDM and printed everything in it, including screws. And knocked him back to reality asking him that.

Also speaking of flat surfaces, the nature of the LCD screens used in these printers make it impossible to print a perfectly smooth flat surfaces. If you position that windshield or any flat surface object vertically you'll notice microscopic vertical lines and that's because the tiny little pixels in the screen are not perfect squares nor perfectly aligned, depending on the tech/manufacturer those pixels could be a series of slots, triangles, parallelograms, etc with the space inbetween them where the traces and other electronics go.

Edited March 2, 2023 by Inquisitor

[ElectroSoldier]

6 hours ago, Inquisitor said:

The opel blitz truck windshield is flat enough that you'd get away with just cutting it out from clear plastic sheet. Even a lot of resin car kits get away with that. 3d printing is not the miracle tool for everything. That's one thing you learn. It not a question of if you can, but should you? My brother got that fever a few years back when he got his first FDM and printed everything in it, including screws. And knocked him back to reality asking him that.

Also speaking of flat surfaces, the nature of the LCD screens used in these printers make it impossible to print a perfectly smooth flat surfaces. If you position that windshield or any flat surface object vertically you'll notice microscopic vertical lines and that's because the tiny little pixels in the screen are not perfect squares nor perfectly aligned, depending on the tech/manufacturer those pixels could be a series of slots, triangles, parallelograms, etc with the space inbetween them where the traces and other electronics go.

Going on that basis it makes me wonder if you would have progressed from resin casting to 3D printing at all.

[Inquisitor]

16 hours ago, ElectroSoldier said:

Going on that basis it makes me wonder if you would have progressed from resin casting to 3D printing at all.

Each method of manufacture have their own pro and cons. Meanwhile 3d printing on the consumer side has progressed by leaps and bounds in the last 5-6 years from 2k to 4k to 8k and some making the jump to DLPs. And we're speaking of consumer grade printers that use masking LCD technology. Most of the industrial grade printers that are in the 5-6 digits price use lasers have been available for even longer.

[ElectroSoldier]

32 minutes ago, Inquisitor said:

Each method of manufacture have their own pro and cons. Meanwhile 3d printing on the consumer side has progressed by leaps and bounds in the last 5-6 years from 2k to 4k to 8k and some making the jump to DLPs. And we're speaking of consumer grade printers that use masking LCD technology. Most of the industrial grade printers that are in the 5-6 digits price use lasers have been available for even longer.

Ive only recently put a toe into the 3D printing world once I saw the results people were getting with the Mighty 8K.

They have 3D printers at my work. its prints are amazing but the price tag matches it.